Field of Invention
The present invention relates to a touch sensing system and a signal operation method of the same. More particularly, the present invention relates to an extended-type multi-touch system and a signal operation of the system.
Description of Related Art
Recently, the touch-sensing electronic products are beloved by the consumers and are gradually become the main tendency because of their ease to be operated and their user intuition operation. Among the conventional resistive touch screen, capacitive touch screen, and rear projection touch screen, the touch efficiency of the capacitive touch screen is better but the cost of the capacitive touch screen is more expensive. Further, with the increasing of the size of the screen, the application of the capacitive touch screen is limited. To pursue the substitution for the capacitive touch screen, currently, an optical touch screen using optical element for detecting touched position is developed and it possesses the advantages of low coast and high accuracy which make it on a relatively vantage position in the highly competitive market. Therefore, it becomes another options for large-size touch screen.
The conventional optical touch screen utilizes at least two sensors each of which is composed of an image sensing unit and a light emission unit and which are configured at the periphery or the corners of the screen. Moreover, the light reflective frames are configured on the periphery of the screen. The light emission units radiate the light onto the light reflective frames and the image sensing units capture the light-and-shade status of the light reflective light from the light reflective frames so that whether there is a physical object on the screen can be determined and the position of the physical object can be calculated as well. However, the size of the conventional touch screen cannot be enlarged over 100 inches or, even the touch screen with large size can be manufactured, the cost is sky high due to changes of the hardware standards.